Deionization technology may herald low cost sea water desalination and waste water treatment.LIVERMORE, Calif.--(BUSINESS WIRE)--Dec. 20, 1994--A process which holds the promise of inexpensive desalination desalination or desalting Removal of dissolved salts from seawater and from the salty waters of inland seas, highly mineralized groundwaters, and municipal wastewaters. of sea water and extraction of harmful contaminants from waste water, as well as other applications, has been successfully demonstrated at Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory: see Lawrence Berkeley National Laboratory. (body) Lawrence Livermore National Laboratory - (LLNL) A research organaisatin operated by the University of California under a contract with the US Department of Energy. . The Laboratory is funded by the Department of Energy. Known as capacitive deionization deionization /de·ion·iza·tion/ (de-i?on-i-za´shun) the production of a mineral-free state by the removal of ions. deionization the production of a mineral-free state by the removal of ions. (CDI CDI compact disc interactive: a system for storing a mix of software, data, audio, and compressed video for interactive use under processor control ), the patented process will consume approximately 100-1,000 times less energy per unit of water purified than does conventional evaporation technology, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. inventor Joe Farmer. Potential applications of CDI are numerous: - Desalination of sea water for residential, commercial and agricultural purposes. - Deionization (purification) of waste water. - Electrically driven water softeners for home use. - High-purity water production for semiconductor processing. - Removal of contaminants in blood with minimal cell damage. The CDI process is relatively simple. At the heart of the system are thin metal plates (electrodes) roughly six inches square and perforated by holes to facilitate stacking. A specialty material known as carbon aerogel aerogel, any of a group of extremely light and porous solid materials; the lightest is less than four times as dense as dry air. Aerogels are produced from certain gels (see colloid) by heating the gel under pressure, which causes the liquid in the gel to become is attached to the plates. Water containing salt, heavy metals heavy metals, n.pl metallic compounds, such as aluminum, arsenic, cadmium, lead, mercury, and nickel. Exposure to these metals has been linked to immune, kidney, and neurotic disorders. or even radioactive isotopes is pumped through electrochemical electrochemical /elec·tro·chem·i·cal/ (-kem´i-k'l) pertaining to interaction or interconversion of chemical and electrical energies. e·lec·tro·chem·i·cal adj. assemblies consisting of a stack of about 50 electrodes. When an electric charge is applied across the electrodes, the negatively and positively charged ions -- for instance sodium (Na+) and chloride (Cl-), in the case of sea water -- are absorbed into the carbon aerogel. By turning off the power, the trapped ions can be released into a relatively small stream of "rinse" water comprising one percent or less than the volume of the initial in-flow. Carbon aerogel is the reason that the CDI process, which is conceptually simple, has suddenly become viable. It is a highly porous and extremely light solid. The carbon version was developed at Livermore a few years ago. Sometimes called "frozen smoke," the surface area of each of the thin sheets attached to a CDI electrode is, incredibly, nearly equivalent to a football field. An attractive feature of the technology is the stackable nature of the electrodes. A home water softener might contain a relatively small number of electrodes. A commercial desalination plant would likely contain thousands and the electrodes would probably be larger, but the fundamental design would be the same. CONTACT: Lawrence Livermore National Laboratory Craig Savoye, 510/422-9919 |
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